Appearing on "Fox & Friends" with hosts Steve Doocy, Ainsley Earhardt, and Brian Kilmeade, MacCallum said that a newly surfaced audio clip from 2015 of the former three-term mayor of New York City will become ammo for others on the debate stage in a "huge way."
In the recording, Bloomberg gives a full-throated defense of the controversial policing procedure known as "stop and frisk." He acknowledged that "stop and frisk," targeted minority "kids" who cops must throw "up against the wall" to disarm.
"Ninety-five percent of murders- murderers and murder victims fit one M.O. You can just take a description, Xerox it, and pass it out to all the cops," he said. "They are male, minorities, 16-25. That's true in New York, that's true in virtually every city (inaudible). And that's where the real crime is. You've got to get the guns out of the hands of people that are getting killed."
Bloomberg also said urban crime-fighting required cities to "spend the money" and "put a lot of cops in the streets," particularly in "minority neighborhoods," where he said the crime is. He also acknowledged the "unintended consequences" of the policy.
"So one of the unintended consequences is people say, 'Oh my God, you are arresting kids for marijuana that are all minorities.' Yes, that's true. Why? Because we put all the cops in minority neighborhoods," Bloomberg is heard saying on the recording. "Yes, that's true. Why do we do it? Because that's where all the crime is. And the way you get the guns out of the kids' hands is to throw them up against the wall and frisk them... And then they start... 'Oh I don't want to get caught.' So they don't bring the gun. They still have a gun, but they leave it at home."
Bloomberg has attempted to apologize for supporting the policy since entering the 2020 Democratic primary, but the issue remains a source of controversy weighing down his candidacy.
"You almost have to wonder, at this point, whether or not he would have been better off just explaining his thinking on stop and frisk and sticking by it," said MacCallum.
"You just think about the way President Trump handles it when he's confronted with anything like that. He just doubles right down and says 'yes,'" she added.
In fact, the president had some choice words for Bloomberg. He tweeted Tuesday morning: "WOW, BLOOMBERG IS A TOTAL RACIST!"
Shortly after, however, he deleted said tweet.
MacCallum predicted that, while there is "some truth to a lot of the facts" in his statement, Bloomberg will have a "hard time on that issue in a lot of places."
"The Nevada debate's going to be a very big moment for him and nobody has seen him get up on stage and talk," she continued. "If you're from New York you have. But, people across the country -- I talked to people up here who said, 'Yeah, I've never really heard him say anything.'"
Fox News' Joseph A. Wulfsohn and Ronn Blitzer contributed to this report.